Telephone cards, which have been widely used recently, are sold and used with a variety of designs, etc. printed thereon. Such telephone cards as having scenery pictures printed thereon as they are and as having specific information of each shop printed thereon for advertising the shop are sold and used. Now, a mechanism of an ordinary telephone set 16 will be explained using FIG. 17 and FIG. 18. A telephone card inserted through a telephone card insertion slot 6 is transferred through a first transfer means 10 to a telephone card fixing part 8. A remaining number-of-calls (messages) of the telephone card is counted by a number-of-calls counting means 12 at the telephone card fixing part 8 and that remaining number-of-calls is displayed by a number-of-calls display means 14. When this remaining number-of-calls is not zero and a receiver 62 is off a receiver receptacle 64, a state capable of number designation is secured by a means 28 to allow an acceptance of a designated number. Ordinarily, continuous sounds, "pi, . . . " are generated. When a number to be called is designated by a number designating means 30 with dial or push button, etc. under such state, the telephone set is placed in a state where speaking with the party called can be made as the party called picks up the telephone set by an action of a circuit coupling means 32. And when the remaining number-of-calls in the telephone card becomes zero or the receiver 62 is placed onto the receiver receptacle 64, the speaking with the other party becomes impossible by an action of a circuit breaking means 38.
In general, telephone cards are consumable commodity made of flexible rigid material, therefore they are ordinarily discarded when used up. Telephone cards discarded can be seen around a public telephone and it is not desirable from the stand point of keeping clean environment.
Also, the trend of providing a variety of elaborate design or pattern printed on telephone cards for securing greater sales is rapidly increasing, therefore telephone cards which have direct and concrete benefits for daily life is rather scarce.
Further, as these telephone cards are made of flexible rigid material being different from paper, they do not easily undergo permanent deformation or destruction.
Under the circumstance, the present invention is made to solve the above mentioned problems while using said special features of telephone cards, and is intended to supply such telephone cards as directly useful for daily life by providing a calendar function on the telephone cards, and to enhance the usefulness of the used telephone cards, and at the same time to provide an advantageous system for using telephone cards.